U.S. Pat. No. 7,635,243 and 2009/0047060 disclose direct load indicating fastener assemblies, also called direct tension indicating fastener assemblies, that include a fastener assembled to a direct load indicating washer. Fabrication of means on the nut or bolt for rotatably mounting the washer is expensive. Furthermore, such washer-mounting means do not accommodate a hardened metal washer between the head of the fastener and the load indicating washer, which is desirable in many applications. A general object of the present disclosure is to provide a direct load indicating fastener assembly that addresses one or more of these shortcomings in the prior art.
The present disclosure embodies a number of aspects that can be implemented separately from or in combination with each other.
A direct load indicating fastener assembly, in accordance with one aspect of the present disclosure, includes a flange fastener of one-piece construction having a head with an integral flange. A load indicator has a flat base, a plurality of protuberances on the base and a peripheral rim. At least a portion of the peripheral rim overlies the fastener flange and captures the fastener in assembly with the load indicator while permitting free rotation of the fastener with respect to the indicator. The fastener preferably is a flange nut or a flange bolt. A hardened metal washer may be disposed between the load-indicating protuberances on the base and an undersurface of the fastener head.